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What weight loss treatments are being studied
GLP-1 and combination medicines. The medicines that reshaped the field mimic a gut hormone called GLP-1 that signals fullness and slows digestion. Semaglutide (Wegovy) was approved for weight management in June 2021 and produced about 15 percent weight loss in its main trial; tirzepatide (Zepbound), which acts on GLP-1 and a second hormone, GIP, was approved in November 2023 and produced up to about 21 percent. Trials now test medicines that add a third hormone signal or pair a GLP-1 with amylin, another appetite hormone, aiming for larger and more durable weight loss; the CagriSema combination, for example, is under FDA review after Phase 3 trials, and its confirmatory studies are still enrolling.
Pills. For years every effective option was an injection. In December 2025 the FDA approved a semaglutide tablet (Wegovy pill), and on April 1, 2026 it approved orforglipron (Foundayo), the first GLP-1 pill that can be taken at any time without food or water restrictions, after trials in which people lost about 11 to 12 percent of body weight over 72 weeks. Current orforglipron trials test the pill in groups the approval studies did not cover, including adolescents and people who have already lost weight on an injection and want to maintain it.
Weight loss surgery. Bariatric surgery remains the most effective and longest lasting treatment for severe obesity, with roughly a quarter of a million operations performed in the US each year, most of them sleeve gastrectomy or gastric bypass. Trials study how surgery changes metabolism, how to prevent weight regain afterward, and how surgery compares with or combines with the new medicines.
Devices and endoscopic procedures. Between medicine and surgery sit procedures done through the mouth with no incision: endoscopic sleeve gastroplasty, which stitches the stomach smaller from the inside and was authorized by the FDA in 2022; intragastric balloons, which sit in the stomach for six months; and revision procedures for people who regained weight after bypass. Trials compare newer devices against established ones and measure how long results hold.
GLP-1 medication trials
GLP-1 medicines copy a hormone your gut releases after eating. They tell the brain you are full, slow the emptying of the stomach, and improve how the body handles blood sugar. The effect on appetite is why they work for weight, and it is also why the most common side effects are nausea, constipation, and diarrhea, especially when starting or increasing a dose. Most GLP-1 trials for weight loss run for 52 to 72 weeks, give the medicine as a weekly injection or daily pill, and measure the percentage of body weight lost compared with a comparison group.
Two things are worth knowing before you apply. First, a placebo is usually part of the design: in a typical trial, some participants receive an inactive injection or pill so that researchers can separate the medicine's effect from diet, attention, and expectation. Assignment is random, you will not know which group you are in, and no one can promise you the active medicine. Many trials offer it to everyone in an extension phase afterward, and the listing will say so. Second, real world data show that most people stop GLP-1 medicines within a year, often because of cost or side effects, so a growing share of trials study how to keep weight off after stopping, or how to switch from an injection to a pill. Our guide to placebo controlled trials explains how these designs protect participants, and our obesity treatment guide covers what each approved medicine has shown.
Weight loss surgery and device trials
Surgical and device studies work differently from drug trials. Most compare two real procedures rather than a procedure and a placebo, for example a new endoscopic stitching system against an established one, or study people who have already chosen surgery to learn how it affects blood sugar, the gut, or the muscles over years. Follow up is long: a surgery trial may see participants for five years or more, because the question is not whether weight comes off but whether it stays off. Some studies enroll people who regained weight after an earlier operation and test revision procedures done through the mouth. Because surgery is a major medical decision, these trials involve the same surgical evaluation, consent, and aftercare as surgery outside a study, and the study team explains during informed consent exactly which costs the research covers and which fall to you or your insurance.
Who can participate in weight loss treatment trials
Most medicine trials enroll adults with a body mass index of 30 or higher, or 27 or higher with at least one weight related condition such as type 2 diabetes, high blood pressure, sleep apnea, or fatty liver disease. Many require that your weight has been stable for the past few months and that you are not currently taking another weight loss medicine. Some are built for specific groups: adolescents, people with type 2 diabetes, people who have already lost weight on an injection, or people with a heart or liver condition. Surgery and device trials usually require a BMI of 35 or higher, or 30 with a related condition, plus a surgical evaluation. People who have had bariatric surgery before are excluded from some studies and specifically wanted by others. Trials use randomization and screening, so meeting the description does not mean a place is certain. Eligibility always varies by study; for the broader picture of who joins obesity research, see our obesity clinical trials page.
Considering volunteering in a clinical trial? Explore our comprehensive guide to learn more about why people choose to volunteer and the impact you can make in advancing medical research. Discover the process of volunteering, what to consider before applying and the potential benefits and risks involved.
Do participants get paid?
Some studies offer compensation for time and travel, and study related care, including the study medicine or procedure and the visits and tests the protocol requires, is typically provided at no cost to participants. Compensation varies by trial and is always described during the informed consent process before you agree to anything. It is never the reason a study exists, and it does not change the fact that assignment to an active treatment or a comparison group is random.
Curious whether clinical trials pay participants? Here's how compensation actually works.
How to enroll in a weight loss clinical trial
Enrolling in a weight loss clinical trial through our platform is a straightforward and user-friendly process. Here's how to get started:
- Find the Right Trial: Start by utilizing our search function or applying filters to narrow down clinical trials that match your interest in weight loss. This step simplifies the process of finding relevant research studies tailored to your needs.
- Select Your Preferred Location: To find trials conveniently located near you, simply input your preferred location into the dedicated filter bar on the left-hand side of the page.
- Explore Study Details: For in-depth information about each study, simply click the “Learn More” button. This will provide you with comprehensive details about the trial, including objectives, procedures, and eligibility criteria.
- Complete the Health Profile: After clicking on the “Get started” button you will be taken to our efficient 5-step application process to provide important health information. This helps us match you with the clinical trial that best fits your needs.
- Submit the Application: After completing the application, send it in. A clinical trial coordinator will review it and contact you regarding the possibility of participation.